Ap.—Apud, in the writings of; as quoted by.
A. P. G. or Ast. P. G.—Professor of Astronomy in Gresham College.
Apo.—Apogee.
Apoc.—Apocalypse.
App.—Appendix.
Apr.—April.
A. Q. M. G.—Assistant Quartermaster-General.
A. R.—Anna Regina, Queen Anne.
A. R.—Anno regni, year of the reign.
A. R. A.—Associate of the Royal Academy.